What does “joint stereo” mean?

Hey, there!

Oh, do tech people love their labels, or what?

Whoever came up with the concept of “joint stereo,” I don’t think he or she had getting high in mind.

Joint stereo actually means something pretty cool, but hardly necessary these days.

Back in the days when the MP3 file format was created, disk space was still fairly expensive.

So it was helpful to be able to save space wherever possible. And encoding stereo files in “joint stereo” did just that: save space.

To understand joint stereo, you have to understand the other option when creating an MP3 file, “true stereo”.

True stereo files contain every single drop of the data that describes the sound of each channel, left and right.

Which means if the strings are on the left and the woodwinds are on the right, all of that encoded data will be there.

But what if it’s a vocalist, right in the middle of the stereo space? That means that the vocalist will be on both channels, with the same data.

And that’s where joint stereo comes in.

Joint stereo collapses file to mono size when it’s appropriate (like when that solo singer is right in the middle of your headphones, holding a long note with no other instruments playing), and blooms back out to stereo size when needed.

It was the MP3 designer’s attempt at saving space by not encoding redundant data when it didn’t have to.

But it’s unnecessary today – storage space is cheap. And truthfully? So few recording situations allowed joint stereo to save appreciable space, it wasn’t all that effective anyway.

So, if you’re creating a stereo MP3 file, you can choose true stereo without fear of using up too much space.


10 Responses to 6 Steps to a Perfect VO Demo

  1. Kelli August 18, 2011 at 2:58 am #

    I feel really good about my demo. It is a quick and fun process, even for someone like me who gets very self concious. :)

  2. David Britz September 5, 2011 at 11:25 pm #

    The demos are great. Superb quality. Why go anywhere else?

  3. David Britz October 20, 2011 at 3:51 pm #

    Can’t wait to record my Narration VO Demo!! :))

  4. Mike Brang December 31, 2013 at 9:44 am #

    Having a well-produced demo is one of the most important things in the VO business. I had a number of demos made from other producers in the past and they all had one thing in common — that manufactured, cookie cutter sound!
    What sets David apart from the rest, besides his affordable price and tremendously fast turn around time, is that all of the clips you record with him sound unique. Each spot sounds like an actual commercial you recorded for a job.
    My agent loved the quality and even asked who produced it to refer his other talent there!

    Thanks again, David for producing such a great, high quality demo for me. You made the process relaxing and enjoyable. I urge anyone reading this unsolicited reply to listen to David’s student demos to hear the difference for yourself. Anyone would be lucky to work with him

  5. Kristy Liles February 9, 2017 at 7:04 pm #

    I can not thank you enough. I worked so hard on 15 page IVR project, one day I cryed, look for answers, pull my hear (not really) but I was about until another VO send me this great tool. Thanks!

  6. Frank June 11, 2017 at 9:51 pm #


    When v123 indicates the audition is for a student/ nonprofit are we to assume it is for $0. If so, why does the audition ask for an amount to be entered?

  7. shirley jordan June 12, 2017 at 5:58 pm #

    I did get this scam through Voice 123. In our discourse, they offered me the gig and they gave me the name of a legit local place to record and the same runaround with the money. I didn’t send anything, but instead, I called the studio to make sure the booking was for the day we set up, and lo and behold, the people there had no idea what I was talking about. I then tried to call back my “contact person” who was setting this up and there was a fax machine beep on the other end. I immediately contacted Voice 123 and told them what had happened. You know what they say…if it sounds togaed to be true, it probably is. Thanks for the reminder!

  8. shirley jordan June 12, 2017 at 5:59 pm #

    …too good…not togaed.
    The one time spell check didn’t work!

  9. Bernard Prame July 1, 2017 at 9:44 pm #

    extremely helpful demo. Thank you!

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